745 research outputs found

    Therapeutic Efficacies of Nano Carriers in Delivering Drugs

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    The drug release rates of poorly soluble medications such as doxorubicin has been investigated in this paper. Since the drug was fixed, different carriers used to deliver it and their release rates compiled from literature were evaluated in this paper. Even though targeting of drugs is very important in drug delivery, it is not within the scope of this paper. However, functionalization of the carrier may provide this benefit, those constructs are included for comparison in terms of hybrid constructs. Dendrimer, micelles and hybrid constructs used in the delivery of doxorubicin compared in this paper with respect to carrier size and drug loading. Assuming that the dissolution follows a slow release, 40-50% of the drug in the phase I representing a sudden or the burst release, followed by a steady release of 50-60% of the drug in phase II, not all the carriers and their sizes exhibited this behavior. Carriers and hybrid constructs 38nm size were more effective where phases I and II observed, however, as the size decreased to 34 nm or increased above 40nm, minimal release occurred meaning the carriers were too big to penetrate the vasculature permeability. Nano-carriers, dendrimers, micelle, hybrid dendrimers and micelles were found to be effective with the carrier manufacturing, generation, polymer, molecular weight of the carrier and other parameters. The release rate of doxorubicin was found to be effective with dendrimers together with hybrid dendrimer exhibiting a bilinear behavior. Micelles 20nm were more effective representing 60% of release in 10 hours followed by additional 25% in 35 hours exhibiting a bilinear behavior. Size greater than 20nm resulted in slow release reaching less than 10 to 40% of drug. Several drugs exhibited multiple slopes in their kinetics when micelle was used. The therapeutic efficacy of hybrid micelle was superior to other nano-carriers

    Therapeutic Efficacies of Nano Carriers in Delivering Drugs

    Get PDF
    The drug release rates of poorly soluble medications such as doxorubicin has been investigated in this paper. Since the drug was fixed, different carriers used to deliver it and their release rates compiled from literature were evaluated in this paper. Even though targeting of drugs is very important in drug delivery, it is not within the scope of this paper. However, functionalization of the carrier may provide this benefit, those constructs are included for comparison in terms of hybrid constructs. Dendrimer, micelles and hybrid constructs used in the delivery of doxorubicin compared in this paper with respect to carrier size and drug loading. Assuming that the dissolution follows a slow release, 40-50% of the drug in the phase I representing a sudden or the burst release, followed by a steady release of 50-60% of the drug in phase II, not all the carriers and their sizes exhibited this behavior. Carriers and hybrid constructs 38nm size were more effective where phases I and II observed, however, as the size decreased to 34 nm or increased above 40nm, minimal release occurred meaning the carriers were too big to penetrate the vasculature permeability. Nano-carriers, dendrimers, micelle, hybrid dendrimers and micelles were found to be effective with the carrier manufacturing, generation, polymer, molecular weight of the carrier and other parameters. The release rate of doxorubicin was found to be effective with dendrimers together with hybrid dendrimer exhibiting a bilinear behavior. Micelles 20nm were more effective representing 60% of release in 10 hours followed by additional 25% in 35 hours exhibiting a bilinear behavior. Size greater than 20nm resulted in slow release reaching less than 10 to 40% of drug. Several drugs exhibited multiple slopes in their kinetics when micelle was used. The therapeutic efficacy of hybrid micelle was superior to other nano-carriers

    Effectiveness of Mesoporous Bioglass in Drug Delivery

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    Since the invention of bioactive glass 50 years ago, it has become a versatile material used in healthcare in a variety of applications and compositions. Bioactive glass has shown superior capabilities of drug delivery compared to traditional carriers. For example, time-released medications are less likely to reach toxic levels, while delivering a specific, therapeutic dose to a localized area. The objective of this paper is to investigate the properties and effectiveness of mesoporous bioglass (MBG) as a drug delivery carrier. A literature review of various polymer coated 45S5 Bioglass® loaded with vancomycin was analyzed to determine their drug release response. Since MBG continues to be a preferred carrier with numerous combinations; size, coating, doped with ions, medications, and other physical conditions, there is a need to understand more fully their effectiveness. For a given loading efficiency of 5-15% the burst release % for day 1 remained 15-30% for given surface area, pore volume and pore size of 3.5 to 5 nm. The mechanical properties summarized in this paper are compared with the drug release kinetics. In general, for a given fracture toughness and compressive strength, the ratio of Young’s modulus to bending strength around 250 determined poor apatite mineralization resulting in slow release. As this ratio increased the apatite mineralization and dissolution rate increased. Doping MBG with ions enhanced the drug efficacy to treat a particular condition, for example, silver. Polymer coated MBG exhibited slower dissolution rate than uncoated MBG. Dissolution time increased with the drug loading rate, drying time of the coating, multi-layer coats of drug and polymer for the drug studied in this paper to more than 50%

    QES-Fire: A dynamically coupled fast-response wildfire model

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    A microscale wildfire model, QES-Fire, that dynamically couples the fire front to microscale winds was developed using a simplified physics rate of spread (ROS) model, a kinematic plume-rise model and a mass-consistent wind solver. The model is three-dimensional and couples fire heat fluxes to the wind field while being more computationally efficient than other coupled models. The plume-rise model calculates a potential velocity field scaled by the ROS model\u27s fire heat flux. Distinct plumes are merged using a multiscale plume-merging methodology that can efficiently represent complex fire fronts. The plume velocity is then superimposed on the ambient winds and the wind solver enforces conservation of mass on the combined field, which is then fed into the ROS model and iterated on until convergence. QES-Fire\u27s ability to represent plume rise is evaluated by comparing its results with those from an atmospheric large-eddy simulation (LES) model. Additionally, the model is compared with data from the FireFlux II field experiment. QES-Fire agrees well with both the LES and field experiment data, with domain-integrated buoyancy fluxes differing by less than 17% between LES and QES-Fire and less than a 10% difference in the ROS between QES-Fire and FireFlux II data

    Open Educational Resources in Kentucky

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    Open educational resources (OER) play an increasingly important role in the education landscape, with increased awareness and use year over year (Coffey). Often, academic libraries play a supporting role for instructors as they locate, adopt, and create OER for their courses. In this article, we will provide an introduction to OER, outline some current trends in open education, and describe a few of the OER initiatives currently underway in Kentucky’s college and university libraries

    Open Educational Resources in Kentucky

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    Open educational resources (OER) play an increasingly important role in the education landscape, with increased awareness and use year over year (Coffey). Often, academic libraries play a supporting role for instructors as they locate, adopt, and create OER for their courses. In this article, we will provide an introduction to OER, outline some current trends in open education, and describe a few of the OER initiatives currently underway in Kentucky’s college and university libraries

    Content validation of the patient-reported outcomes measurement information system (PROMIS) framework in women with urinary incontinence

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    Aims To assess whether the existing National Institutes of Health (NIH) Patient Reported Outcomes Measurement Information System (PROMIS) conceptual framework and item banks sufficiently capture the concerns of women with urinary incontinence (UI). Methods Thirty-five women with UI were recruited between February-April 2009 for 4 structured focus groups to develop and assess the content validity of a conceptual framework for the impact of UI. This framework included domains from the NIH PROMIS framework and item banks including broad domains of physical and social function and mental health. All sessions were transcribed, coded, and qualitatively and quantitatively analyzed using analytic induction and deductive analysis to identify new themes and domains relevant to women with UI. Results The focus groups provided information that confirmed the relevance of existing PROMIS domains and identified new outcome domains that are important to this patient population. The groups confirmed the relevance of the physical and social functioning, and mental health domains. Additional themes that emerged included the distinction between ability versus participation and satisfaction, role functioning, external mediators, re-calibration/coping, cognitive function and new possibilities. Participants also felt strongly that not all domains and items apply to all women with UI and an option to tailor questionnaires and skip non-relevant items was important. Conclusions The PROMIS framework domains are relevant to women with UI, but additional patient-important themes are identified that may improve the comprehensiveness of this assessment framework for measuring outcomes important to women with UI. These results will inform future item content development for UI. 30:503–509, 2011. © 2011 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83737/1/21048_ftp.pd

    Overcoming barriers to engaging socio-economically disadvantaged populations in CHD primary prevention: a qualitative study

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    <p><b>Background:</b> Preventative medicine has become increasingly important in efforts to reduce the burden of chronic disease in industrialised countries. However, interventions that fail to recruit socio-economically representative samples may widen existing health inequalities. This paper explores the barriers and facilitators to engaging a socio-economically disadvantaged (SED) population in primary prevention for coronary heart disease (CHD).</p> <p><b>Methods:</b> The primary prevention element of Have a Heart Paisley (HaHP) offered risk screening to all eligible individuals. The programme employed two approaches to engaging with the community: a) a social marketing campaign and b) a community development project adopting primarily face-to-face canvassing. Individuals living in areas of SED were under-recruited via the social marketing approach, but successfully recruited via face-to-face canvassing. This paper reports on focus group discussions with participants, exploring their perceptions about and experiences of both approaches.</p> <p><b>Results:</b> Various reasons were identified for low uptake of risk screening amongst individuals living in areas of high SED in response to the social marketing campaign and a number of ways in which the face-to-face canvassing approach overcame these barriers were identified. These have been categorised into four main themes: (1) processes of engagement; (2) issues of understanding; (3) design of the screening service and (4) the priority accorded to screening. The most immediate barriers to recruitment were the invitation letter, which often failed to reach its target, and the general distrust of postal correspondence. In contrast, participants were positive about the face-to-face canvassing approach. Participants expressed a lack of knowledge and understanding about CHD and their risk of developing it and felt there was a lack of clarity in the information provided in the mailing in terms of the process and value of screening. In contrast, direct face-to-face contact meant that outreach workers could explain what to expect. Participants felt that the procedure for uptake of screening was demanding and inflexible, but that the drop-in sessions employed by the community development project had a major impact on recruitment and retention.</p> <p><b>Conclusion:</b> Socio-economically disadvantaged individuals can be hard-to-reach; engagement requires strategies tailored to the needs of the target population rather than a population-wide approach.</p&gt

    Analysis of six “neuro-enhancing” phenidate analogs

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    Six collected phenidates, i.e. 4-methylmethylphenidate, 3,4-dichloromethylphenidate, ethylphenidate, 3,4-dichloroethylphenidate, ethylnaphthidate and N-benzyl-ethylphenidate were fully characterized by means of X-ray, NMR, GC-MS, ESI-MS2, ATR-FT-IR and GC solid-state IR analysis. Crystallography revealed the exclusive presence of the threo-configuration. Steric crowding induced by N-benzyl substitution at the piperidine moiety prompted an adoption of an unexpected axial positioning of substituents on the piperidine moiety in the crystal state as opposed to the exclusive equatorial positioning encountered in N-unsubstituted phenidate analogs. Gas phase computations of the relative lowest energy conformers confirm that the axial positioning appears to be favored over the equatorial positioning, however in solution equatorial positioning is predominant according to NOE experiments. All samples, mainly originating from China, had a good to very good degree of purity indicative of their professional chemical synthesis. Routine analysis of these drugs by GC-MS revealed thermal decomposition of phenidate analogs in the injection port and/or on column to 2-aryl-ethyl-acetates and 2,3,4,5-tetrahydropyridines. The decomposition pathway was suggested to proceed via a 6-membered transition state which was supported by DFT-computations. Fragmentation pathways of decomposition products as well as the corresponding EI mass spectra are provided. The thermal instability might thus render smoking or “vaping” of these drugs a less effective route of administration. The analytical fingerprints of six structurally diverse phenidate analogs provide a helpful reference to forensic chemists in charge of identifying new psychoactive substances

    Seven fatalities associated with ethylphenidate

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    Ethylphenidate is a stimulant novel psychoactive substance that is an analogue of the prescription drug methylphenidate (Ritalin®). Methylphenidate is used commonly for the treatment of attention deficit hyperactivity disorder. Due to its stimulant effects ethylphenidate is being abused. There is a single case report of a death associated with ethylphenidate in Germany, and a case series of 19 deaths in the East of Scotland, but otherwise, the contribution of ethylphenidate to death is poorly documented. We report the analytical results of 7 cases (between February 2013 and January 2015) in which ethylphenidate was detected and quantitated with a validated liquid chromatography tandem mass spectrometry method (LC-MS/MS). The individuals (all male) ranged in age from 23 to 49 years (median 25 years). The concentration of ethylphenidate in the cases ranged from 0.026mg/L to 2.18mg/L in unpreserved post-mortem femoral blood. Only one case had ethylphenidate present as a sole drug. All other cases had at least 2 other drug classes present (benzodiazepines, heroin, methadone antipsychotics, other new psychoactive compounds). Ethylphenidate toxicity was the sole contribution to the cause of death in one case. Hanging was the cause of death in 2 cases, with the other 4 cases being reported as having occurred due to mixed drug toxicity. These data will further help with the interpretation of post-mortem ethylphenidate levels
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